We walk on vast flood plains. Beneath our feet, the firmness of the ground seemsÂ toÂ confirm the permanence of the river channel. To hold up the banks, we press rocks and concrete…. But there is no telling what may happen when the snow thaws or the next rain comes. The bend in the distance may straighten and, suddenly, the landscape is no longer recognizable. We learn in time that we do not control the ultimate shape of things.